Not sure if this is the right sction for this, if it's not then sorry
But i've seen a few players that have been customized to look like they've been assimilated. Is this a vet reward? or does a option to customize sihps like this open up after a certain mission for anything?
The borg pieces are gear you get from the STFs, 5 EDC a piece I believe. There is the Impulse engine, Shield, Deflector. There is also a universal console which you get for completion of the Assimilated mission in the Undine story arc. There are also set bonuses for each piece you aquire and honestly most people will tell you that the bonuses from the set are still superior to any other set out there.
The console adds some nodes (for lack of a better term) to your ship. The engine puts an extra bit on the outside of one impulse engine and a large piece on the opposite nacelle. The deflector well... borgifies your deflector, and the shield gives your hull plating some borg bits.
Yes. I prefer not to display them myself (it is an option on any piece that alters your ship's appearance).
I don't really care for the asymmetrical look of the set myself, but, if you kind of close one eye and look at my ship sideways for a second while the borg visuals are enabled, it does look a bit more Romulan and a bit less Fed. :p